Such a magnetic field sensor may be used in a wide range of applications, namely everywhere where the direction of a magnetic field in a plane needs to be measured. Such applications include angular position measurement in an angle encoder that contains a magnet that is rotatable on an axis, use in a compass and others.
Angular position microsystems based on the magnetostatic principle mostly derive benefit from a Hall-effect sensor. They are composed of a two-dimensional sensing part combined with a rotating permanent magnet. One technique using a magnetic field concentrator is known from EP 1182461. Another technique is known from WO 9810302. Yet another technique uses a special vertical Hall sensor as described in an article available on the Internet http://www.novotechnik.com/pdfs/Vert-X.pdf. A drawback of the known techniques consists in that complex mathematical calculations have to be performed to derive the information on the direction of the magnetic field from the output signals of the Hall-effect sensor.